Television system



June 16, 1931. T, sMlTH TELEVISION SYSTEM Filed July 19, 1929 INVENTOR T. A. SMITH BY ATTORNEY Patented June 16, 1931 UNITED STATES PATENT 1 OFFICE rrmonoan a. smrn, or nmoawoon, mew mnsEY, assIeNon 'ro mm com-om- TION OF AMERICA,

A conronanorr or nnmwaan Y TELEVISION- SYSTEM- Application flled July 19, 1929. Serial No. 879,884.

. The present invention relates-to television systems, and, in particular, to television systems in which the television subject transmitted is a motion picture film, or the like, with or without a sound accompaniment.

In the motion picture art, and, particularly, in the motion picture art as now developed using sound accompaniment, which is placed directly on the motion picture film, or which is on a record adapted to run in synchronism with the motion picture film, it is customary to operate the film at aproj ection speed of twenty-four film frames per second $11108 it has been found that better projection is produced in this manner, and also, and perhaps more important, because of the fact that it has been'found necessary and desirable to use such speeds in order to have a good sound record accompany the film.

Also in television work, it willbe readily recogmzed that the frequency band required for television transmission of pictures, motion picture films, and the like, is a direct function ofthe number of complete pictures transmitted per second, that is, for example, a transmission of twent -four pictures per second would require a fty percent greater frequency hand than a transmission of sixteen pictures per second, due to the fact that there are eight more complete pictures to be transmitted during the same period of time. It will also be immediately recognized, if a motion picture film with a sound thereon is to be projected at a speed such that the frequency band may be conserved as much as possible by reducing the number of complete frame transmissions per second to a number such as twenty, for example, that the action portrayed on the film would be slowed down, and the music or speech reproduced from the sound track would contain wrong frequencies, that is, each note would be reduced in pitch by an amount pro ortionate to the reduction in speed of the 'lm from that speed for which it was produced to be run.

It is, therefore, a principal object of my invention to rovide a television transmitting system w ich may be adapted fortran'smitting motion pictures by television when speed from record the number of complete television images to be transmitted per second is different from the number of frames on the transmitted film which normally pass the projection aperture or scanning device in the same time period.

Still another object of my invention is to provide a method and means by which a mo tion picture film may, in effect, e transmitted over a television transmitter at a reduced which it was originally made to be run, while, at the same time, the sound accompanying the film ma be transmitted at the roper rate' of spee originally produced.

Still'other objects of my invention are to provide a system for transmitting by television the action on a'motion picture film, and, also, the sound record accompanying the action, which is relatively simp e in its construction and arrangement of parts, a system which is compact, conveniently installed, easily operated, readily set up, and

efficient in its use.

Still further objects will suggest themselves and at once become apparent to those skilled in the art to which the invention relates by reading the followin specification and claims in connection wiai the accompanying drawings, wherein:

Fig. 1 represents in a diagrammatic manner one form of apparatus by which the results of my invention may be practiced; and,

Fig. 2 re resents a modified form of arrangement or reducing results similar to those obtained t rough use of the apparatus shown by Fig. 1.

'In considerin this invention, I have illustrated, and Wlll describe by way of example, a system by which motion plcture film avin a sound record thereon, which is designe to be projected through a motion picture projector at twenty-four picture frames for which it was her of individual frame transmissions per second, it will, of course, be recognized that the invention is not limited to such an arrangement but that other numbers of transmissions per second of the individual frames of the film may be substituted for the twenty projections per second described where desired.

Referring now first to Fig. 1 of the accompanying drawings, light produced in a light producing system 1 may be projected on a rotating disk element 2 through any appropriate form of lens system 8 so as to be-concentrated on the disk over a portion thereof including the apertures or lenses arranged in spiral fashion thereon. As I have shown the disk member 2, I have provided five distinct spiral tracks of apertures or lenses in which each spiral has such a pitch that when light from thefirst and last holes of the series is projected on the motion picture film 4, the vertical distance between the first and last holes of each individual spiral will be equal to the height of one frame of the film. as shown on the film by the lines extending transverse thereto. The number of apertures or lenses (only a few of which are shown on the spiral tracks) contained in each individual. spiral is the same as would he found in any ordinary disk constructed in accordance with the teachings of Nipkow, and this number is, of course, determined and is a direct function of the amount of detail which is desired in the received picture.

As shown, the disk member 2, containing five spiral tracks, to be hereinafter described in further detail and function, may be rotated by a motor 5. and, if it is assumed that twenty complete pictures per second are to ,be projected at the receiver screen, it will be recognized that the motor 5 should rotate at 1200 revolutions per minute. As is well known in the art the rotation of the scanning disk provides a means by which successive apertures or lenses cause a point of light to trace paths across the subject in such manner that the entire subject is traversed and scanned by a series of parallel lines during a single rotation of the scanning disk. Thus, sequential elements of the subject are scanned in a line for line manner.

The same shaft from the motor which turns the disk member 2 also drives, through an appropriate gear system, a rotary shutter element, generally designated as 6, and, at the same time, drives a pair of sprocket wheels 7 by means of appropriate bevelled gears 8 at such a speed that twenty-four frames of the motion picture film pass by the sprockets each second. Thus, I have pro vided an arrangement wherein a motion picture film 4 may be continuously fed forward with respect to its drive means at such a rate that twenty-four pictures pass in front of the television scanning system each second in contrast to an intermittent type of film feeder, such as is usually used in motion picture projecting apparatus.

To refer now more particularly to the shutter disk 6, I prefer to construct this element of very thin material such as is light and which can be rotated without the need of high power driving devices, and about the periphery of the disk 6, I provide a plurality of specially shaped radial slots 6 which are cut into the surface. Through the gear drive means 21 from the motor shaft to the disk 6, 1 provide an arrangement such that for one complete revolution of the motor shaft the disk element 6 will be rotated or moved downwardly with respect to the five spiral tracks contained upon the disk 2 an amount equal. to one-fifth of the complete spiral pitch of the entire disk 2. The slots on the periphery of the shutter disk 6 are so spaced apart that the distance between spacings is equal to the complete width of holes or apertures on one track of the spiral disk, and the purpose of the shutter 6 is to prevent light from passing through more than one hole, aperture or lens, in the spiral disk at the same time. Thus, light is passed through the top spiral, then as the slot moves lower, through the next spiral and when five revolutions of the motor have occurred, the next successive slot allows from the first spiral to again pass.

Light from the aperture or lens in front of a slot passes through a lens system 9 beyon d the shutter disk'fi in such a manner as to be focused upon the film 4, and with the film t moving upwardly in the direction shown by the arrow, the light beam is gradually caused to traverse the entire film in a line by line manner.

Behind the film 4 and in the path of the light rays passing therethrough from the lens system 9, T have arranged a lens system 10 adapted to collect the light rays and project the same upon a photoelectric member or cell ll which then converts the light striking the cathode thereof into electrical energy in well known manner. The photoelectric cell 11 may then be connected in proper and appropriate manner with an amplifying and trans mitting system so as to transmit electrical energy corresponding to the intensity of light and shadow on the motion picture film to any desired point. This transmission may be by wire, radio, or wiredradio systems, and, in general, as to the specific details thereof, forms no specific part of this invention only in so far as the transmission is necessary to accomplish the results desired.

Located above the light projecting system for analyzing each individual frame of the film as regards the intensity of light and shadow portraying the action thereon so as to affect the photo cell 11 proportionately, I have arranged a sound head, generally designated as 12, which consists of a light source 13 light of substantially constant intensity adapted to project the rays issuing therefrom through a lens system 14, and to concentrate this light upon a slit 17 directly adjacent the sound track on the film. A lens system 15 collects the light which passes through the sound track on the film and projects it upon the cathode of a second photoelectric cell 16. Thus, the light which strikes the photo cell 16 as projected thereon through the slit 17 is a direct function of the sound intensity recorded on the side of the motion picture film strip. Thus, where a variable density sound track record is used, for example, the light striking the photo cell 16 is a function of the density of recording and for high lights on the sound track more current will flow from the photo cell than for low or blackness on the sound track, so that as the film is moved through the sound head sequential elements representing sound may be converted into electrical energy pulses.

Similarly to the photo cell 11, the photo cell 16 may be connected through any appropriate form of amplifier and transmitter and arranged to modulate transmitted energy in accordance with the current flow therethrough as produced by the light striking the same from the sound record on the film.

Where desired, the transmission of both the television picture, as determined by the scanning due to the disk arrangement 2, and the sound record as produced and translated by the photo cell 16, may be transmitted as two independent transmissions, or, where desired, these two signals may be transmitted simultaneously through the use of transmitting arrangements and systems of the type disclosed and claimed in Patent No. 1,770,205, issued July 8, 1930 to Alfred N. Goldsmith and Juliusweinberger, and also by the system disclosed in my copendin application which was filed jointly with Julius Weinberger and George Rodwin on March 25, 1929, as Serial No. 349,834.

In operation of an arrangement of the type disclosed by. Fig. 1, it will be seen that the film moves too rapidly upward to transmit only twenty pictures a second, and to compensate for this, the scanning holes move upward also as is provided by the spiral disk arrangement of scanning. If the film is arranged to move upwardly in the directionshown by the arrow at the rate of twentyfour film frames per second, and the light beam moves upward at the rate of four film frames per second, then the resultant velocity of the film relative to the light spot or scanning apertures is twenty frames per second, which is the assumed desired rate of scanning. At the end of the fifth frame of scanning, instead of continuin the next frame below, the spiral on the isk jumps from the centermost hole-to the outermost hole, and this causes one frame on the film to be omitted and the scanning to continue on the next frame. It will be noted that although light on the disk moves from top to, bottom, the lens 9 reverses the light motion on the film where it moves from bottom to top, that is, it has an upward velocity until it jumps downward an amount equalto the height of one frame.

To refer now to Fig. 2, a modified form of arrangement of the system shown by Fig. 1 has been illustrated, wherein, a system is provided for projecting the light from the light source 1 directly upon the film 4 by means of a lens system 3, and, thus, an image of the film 4 is projected upon the disk 2 by means of the lens system 9. In this arrangement also, the disk 2 is of similar construction and arrangement to the disk previously described in connection with Fig. 1, and the shutter disk 6 also has a corresponding number of slots to the disk G of Fig. 1, which allows light from only one hole at a time to pass through it, and, likewise similar to the construction shown by Fig. 1, a lens 10 and a photo cell 11 serve purposes similar to those above described.

Also, as was described in connection with Fig. 1, a sound head may be placed above the projection apparatus for projecting the film upon the photo cell so that the-sound record accompanying the film may likewise be transmitted simultaneously with the film.

It is also to be recognized that I have by this arrangement only shown two sprocket Wheels in connection with the arrangement of Fig. 1 for driving the film, and in connection with Fig. 2, I have shown a similar arrangement but, where desired, I may modify this arrangement and provide more sprockets or addltional drive means where necessary in order to maintain a continuous and even motion of the film with respect to the light and sound scanning mechanisms.

From the above, it will be seen that I have provided a method and means by which a motion picture film may be so transmitted that the sound record thereon is rojected and transmitted at the normal rate fbr which it is designed, while at the same time I have provided a scanning and analyzing system for the television transmission of the action on the film such that this acton is transmitted at a different rate from which the film is roduced in that five sixths, asabove descri d, of the distinct frames of the picture are projected. However, it will be noted that no material disadvantage is occasioned by such transmission in that the motion ofithe film will not be noticeably different as regards the omission of every sixth frame thereon, as above disclosed.

Still other modifications and changes will suggest themselves and at once become apparent to those skilled in the art, and, therefore, my invention is to be considered in a broad and unlimited sense, and I believe myself to be entitled to make any and all modifications such as fall fairly within its spirit and scope.

Having now described my invention, what I claim and desire to secure by Letters Patent is the following:

1. A system for the electrical transmission of motion picture film which includes in combination means for moving a motion picture film at a predetermined constant speed relative to a predetermined point, and means for scanning a lesser number of picture frames of the motion picture film than pass before said predetermined point during a unit time period.

2. A system for the electrical transmission of motion picture film which includes in combination means for moving the motion picture film in a continuous manner past a given point such that a predetermined number of film pictures pass before said point in a unit period of time, and a scanning device for analyzing the picture elements of a number of picture frames of the said motion picture film per unit of time different from the number of said frames passing before said point in the same unit time period.

3. A system for the electrical transmission of motion picture film which includes in combination means for moving the motion picture film relative to a fixed scanning point at a constant speed such that a predetermined number of picture frames pass before the said point in a unit period of time, and a disk and shutter means for analyzing the picture elements of a number of film picture frames per unit of time different from the number passing before said scanning apparatus.

4. A system for the electrical transmission of motion picture film which includes in combination means for moving the motion picture film relative to a fixed scanning point at a constant speed such that a predetermined number of picture frames pass before the said point in a unit period of time, and a multiple spiral rotatable disk and cooperating shutter means for analyzing the picture elements of a number of film picture frames per unit of time different from the number passing before said scanning apparatus.

A system for the electrical transmission of motion picture film having a sound accompaniment therewith including in combination a scanningelement adjacent the picture film to be transmitted, means for moving the film in a continuous manner relativeto said scanning element, a light responsive element cooperating with said scanning element, and a shutter element interposed between said scanning element and said light responsive element for causing said scanning element to scan a lesser number of picture frames per unit of time than pass before said scanning element.

6. A system for the electrical transmission of motion picture film having a sound accompaniment therewith which includes in com ination a disk having a plurality of paths of spirally arranged scanning elements thereon for scanning the film, means for rotating said scanning disk at a predetermined speed, means for moving the film in a continuous manner relative to said scanning disk at a predetermined speed, a shutter disk for causing said scanning disk to scan a lesser number of picture frames per unit period of time than pass before said scanning disk, and a sound head for converting recorded sound impulses accompanying said film into electrical impulses at a rate corresponding to the number of picture frames passing said scanning disk in the same Lmit period of time. i

7. A system for the electrical transmission of motion picture film having a sound accompaniment therewith which includes in combination a scanning device for scanning the picture elements of the film, means for moving a predetermined number of picture frames of said film per unit time period in a continuous manner relative to said scanning device and said sound head, means for scanning and converting into television signals a lesser number of picture frames than pass said scanning device in the said unit period of time, and a sound head means for converting the film sound accompaniment into electrical energy at a rate corresponding to the number of picture frames moved past the said sound head in the said unit period of time.

8. A system for the electrical transmission of motion picture films which includes in combination a scanning device for scanning the picture film, means for continuously moving the picture film relative to said scanning device at a predetermined number of picture frames per unit period of time. and means providing for the scanning of the individual picture frames of said film in such manner that the number of frames Scanned per unit period of time is unequal to the number of picture frames passing said scanning device in said unit period of time.

9. The method of electrically transmitting motion picture films having a sound accompaniment therewith which comprises converting said sound indications into electrical impulses at a predetermined rate and simulta-neously converting the picture elements of the film into electrical impulses at a lesser relative rate.

10. The method of electrically transmitting motion picture films having a sound accompaniment therewith which comprises analyzing the said sound record at a rate corresponding to a predetermined frame projection rate, and analyzing the picture elements of the film at a rate different from the predetermined frame projection rate.

11. The methodof electrically transmitting motion picture films having asound accompaniment which comprises electrically transmitting the sound accompaniment at a rate commensurate with the sound pitch thereof and simultaneousl transmitting the at a different rate. r

l 12. The method of electrically transmitting motion picture films having a sound accompaniment which comprises electrically transmitting the sound accompaniment at a rate commensurate with the sound pitch thereof and simultaneouslfiyi transmitting the picture elements of the m at a rate less than that commensurate with the sound pitch.

13. The method of electrically transmit-.

sion of motion picture film which includes, in

combination, means for moving a motion picture film at a predetermined constant speed relative to a predetermined point, and means for scanning a number of picture frames of the said motion picture film different from the number of picture frames thereon passing before said predetermined point during a unit time period.

15. A system for the electrical transmission of motion picture film having a sound accompaniment therewith which includes, in combination, means for analyzing the sound accompaniment at a rate corresponding .to a predetermined frame projection rate and means for simultaneously analyzing the picture frame portion at a rate diiferent from said predetermined frame projection rate.

16. A system for the electrical transmission of a motion picture film and a related sound accompaniment which includes, in combination, means for converting the sound accompaniment into electrical energy at a rate corresponding to a predetermined picture frame projection rate, and means for simultaneously converting the picture into electrical energy at a rate different from'the predetermined frame projection rate for sound accompaniment.

17. A system for the electrical transmis: sion of motion picture film having a sound accompaniment therewith which includes, in

combination, means for converting the sound accompaniment recordings into a series of electrical impulses at a predetermined frame projection rate, and means forsimultaneously converting the sequential picture elements into a series of electrical impulses at a rate different from the predetermined frame projection rate.

18. A system for the electrical transmission of motionpicture film having a sound accompaniment therewith which includes, in combination, a sound head for converting sequential sound recordings into electrical current impulses, and a scanning device for converting sequential elements of a picture into a series of electrical impulses at a rate different from the predetermined frame projection rate.

19. A system for the electrical transmis sion of motion picture film and a related sound accompaniment which includes, in combination, a sound converting vmeans for converting sequential sound recordings into electrical current impulses at a rate corresponding to a predetermined film projection rate, and a scanning device for converting se quential elements of a picture into a series of electrical impulses at a rate different from the predetermined film frame projection rate.

20. A system for the electrical transmission of motion picture film having sound recordings thereon which includes, in combination, means for moving the motion picture film relative to a fixed point at a constant speed such that a predetermined number of picture frames pass before the midpoint in a unit period of time, a sound head for converting the sound recordings on the film into electric current impulses at a rate corresponding to the rate at which the picture frames pass before said point, and a scanning device for analyzing the picture elements of a number of film picture frames per unit of time different from the number of frames passing said point per unit period of time.

21. A system for the electrical transmission of motion picture film having a sound accompaniment therewith which includes, in combination, means for moving the film in a continuous manner relative to a predetermined point at a predetermined frame pro jection rate, a sound head for converting recorded sound impulses accompanying said film into electrical im ulses at a rate corresponding to the num er of picture frames passing said predetermined point per unit eriod of time, and a rotary scanning element DISOLAI MEIR 1,810,188.-The0d0re A. Smith, Ridgewood, N. J. TELEVISION SYSTEM. Patent dated June 16, 1931. Disclaimer filed March 4, 1937, by the patentee; the assignee, Radio Corporation of America, consenting. Hereby enters this disclaimer to claims 9, 10, 11, 12, 13, l5, 16, 17, 18, and 19 in said specification.

[Ofiicial Gazette Zl larch 30, 1987.] 

